Answer:
angle 1 is 42
angle 2 is 138
angle 3 is also 42
Step-by-step explanation:
for angle 1, I don't remember what the exact rule was but basically since they are opposite of each other they are equal
for angle 2 all you have to do is subtract 42 from 180 because line n is at an angle of 180 and line m simply splits it into two pieces
for angle 3, I dont remember what the exact rule is or hot to explain it well but it is also 42
